European Hematology Association: Bleeding or Clotting in Elderly Patients with Cancer-Associated Venous Thromboembolism: Which is Worse?

The risk of blood clots in the veins of the legs or the lungs, known as venous thrombosis (VTE) is higher in cancer patients, and so is the risk of bleeding. Whereas anticoagulant therapy lowers the risk of thrombosis recurrence, it further increases the risk of bleeding. Previous studies suggested that the risks of dying from a thrombosis recurrence or bleeding are similar, but such findings may not apply to cancer patients. We aimed to determine the risk of dying from a thrombosis recurrence or bleeding in patients with cancer and thrombosis. We used administrative databases to conduct a population-based retrospective cohort study in Ontario, Canada, including patients 65 years old and older with cancer and a VTE diagnosed within six months of the cancer diagnosis. We estimated the VTE recurrence and major bleeding (MB; defined as gastrointestinal or intracranial) and the 7-day mortality after VTE recurrence or MB events, as well as the ratios of the mortality for MB compared to VTE recurrence. Between 2004 and 2014 we included 6967 VTE events (mean age 75 years, 52% male) treated primarily with low molecular weight heparin or warfarin, either alone or in combination. At six months of the initial VTE there were 3% MB events and 17% VTE recurrences. The 7-day mortality rate was 0.5% for VTE and 11% for MB with a ratio of 21.8 (95% CI 9-53). There were no differences between anticoagulants. This study suggests that the use of anticoagulants in patients 65 years or older with cancer-related thrombosis results in an at least nine times higher mortality if they develop a major bleeding event, compared to a VTE recurrence. This information should be confirmed in further studies and taken into account when designing studies and interventions in this population.

Topic: ASSESSING THE RISK-BENEFIT OF ANTICOAGULANTS IN ELDERLY PATIENTS WITH CANCER-ASSOCIATED VENOUS THROMBOEMBOLISM: A POPULATION BASED STUDY

Abstract S441 will be presented by Alejandro Lazo-Langner on Saturday, June 24, 11:30 - 12:45 in Room N103.

About the EHA Annual Congress Hematology is a specialty that covers everything to do with blood: its origin in the bone marrow, diseases of blood and their treatments. The latest data on research and developments will be presented. The topics range from stem cell physiology and development, to leukemia, lymphoma, myeloma - diagnosis and treatment; red blood cells, white blood cells- and platelet disorders; thrombosis and bleeding disorders.